Railway switch circuit controller



Jan. 29, 1935. I H. L. BONE 1,989,128

RAILWAY SWITCH CIRCUIT CONTROLLER Filed Jan. 16, 1935 5 Sheets-Sheet lINVENTOR Q Q HePbePzLBone N BY QRVTNW HIS A TTORNEY Jan. 29, 1935, H. L.BONE RAILWAY SWITCH CIRCUIT CONTROLLER Filed Jan. 16, 1953 3Sheets-Sheet 2 ww w: @89 E R0... V. mu w No 0 m WMWA r a a a H Jan. 29,1935. H E 1,989,128

' RAILWAY SWITCH CIRCUIT CONTROLLER Filed Jan. 16, 1933 5 Sheets-Sheet 3I y l 80 78 7 95 09 5,5 way INVENTOR Herbam L .60129 BY $11M H16ATTORNEY Patented Jan, 29, 1935 PATENT QFFZICE RAILWAY SWITCH CIRCUITCONTROLLER Herbert L. Bone, Swissvale, Pa., assignor to'The Union Switch1' & Signal Company,

Pal, a corporation of Pennsylvania Application January '16,

v Swissvale,

1933, Serial No.- 651,933

a 9 Claims. (om t-253) 'My invention relates to railway switch'c'ircuitI controllers.

Circuit controllers embodying my invention are particularly suitablefor, although in no way limited to, use in connection with springswitches of the type which are provided with a facing point look soconstructed that when the switch points occupy their normal positions,the'loeking plunger of the lock will normally occupy a locking .posi--tion, but that-When a train trails the switchthe locking plunger willbe automatically withdrawn from its locking positiontounlock the switchby means mechanically actuated by the train, and that when the movablerails have been returned to their normal positions upon completion ofthe trailing movement, the locking plunger will be automaticallyrestorted to its locking positionby spring means to relock-the switch.

One object of my invention is to provide means for detecting improperadjustment or operation of the lock in a spring switch of the typedescribed.

'Another object of my invention is to provide a latching mechanism forlatching the point detector contacts open until they are'manuallyreleased in the event that the switch points fail .to becomeunlocked inthe normal manner'while a train is trailing the switch.

Specifically, circuit controllers embodying my invention are animprovement upon the circuit controller described in my copendingapplication ,for. Letters Patent of the United States, Serial .No.v620,421,.fi1ed July 1, 1932, for Railway switch operating apparatuswhich has matured into Patent No. 1,976,827, dated October15, 1934.

I will describe one form of circuit controller .embodying my invention,andwill then point out the novel features thereof in claims.

In the accompanying drawings, Fig. l is a top plan view showing a springswitch'A controlled by a switch operating mechanism B provided with acircuit controller E constructed in accordance with my invention. Fig. 2is an enlarged transverse sectional view of thespring connecting rod Cforming part of the apparatus illustrated in Fig. 1. Fig. 3 is anenlarged top plan view of the switch operating mechanism 13 and thecircuit controller E shown in Fig. 1, with the various cov ers removedto better illustrate the various details of construction. Figs. 4, 5, 6,7, and 8 are detail sectional views taken substantially on the linesIVIV, VV, VI-VI, VIIVII, and VIIIVIII of Fig. 3, respectively.

Similar reference characters refer parts ineach of the-several views.

attachedtothe operating rod 9.

to similar an adjustable link 49 with the pistonrod 50' oi a Referringfirst to Fig. 1, the reference character A designates a railway switchcomprising, as usual, two fixed rails l and 1 and twomovable rails 2 and2 The fixed rails 1- and 1 are-laid on tie plates 3 and are securedtocrossties 4 in -When the switch occupies its normal position in whichposition it is shown in" Fig. 1, the movable rail 2 engages the fixedrail 1, andthe movable rail'2 is spaced a slight distance fromthe-fixed:rail 1 When the switch is reversedihowever, themovable rail 2 'thenengages the fixed rail 1 and the movable rail 2 is spaced from the fixedrail 1. Y

' The spring connecting rod C may have any suitable form, but in thewell known form-here illustrated, this connecting rod'comprises acylin-'drical housing 10 having a lateral extension'lO "fastened to the headrod-6 (see Fig. 2). The lower end 10 of the housing 'lo has a smallerdiameter than the body of the housing, while the upper end is threadedtoreceive a cap 11 having an end l1 similar to the end at 10*. Slidablymounted in the opening in the end 10 is a-sleeve 12 provided with anannular'fiange 12 located within the housing 10,- and similarlymountedin the opening in the end 11 is a sleeve 13' provided with an annularflange 13 which is also located within the housing 10. A spring rod 14extends through the sleeves l2 and 13 withsu'fficient clearness topermit the rod to slide'freely in the sleeves, and this rod carries acompression spring 15 which engages the sleeves at their annular flangesand urges the sleeves toward the-positions in which the annular flange12 of the sleeve 12 engages the shoulder formed-on the inside of thehousing 10 by the end 10 andthe annularfiange 13 of 'the sleeve 13engages the shoulder formed on the inside 'of the cap 11 by :the end 11The spring'rod l-is provided with an annular shoulder 16 for 'attimesengagingthe -'outer end of the sleeve 12 and with a nut 1'7 for at timesengaging "the outer end of thesleeve 13. The lower end of the spring rod14 ispivotally The operation of the spring connecting rod C is wellunderstood and need not, therefore be describedhere.

The head rod 6 is also connected by means of buffing device D. Thisbuffing device may be of any suitable type but, as here shown, thisbuffing device is similar in all respects to the buffing device shownand described in Letters Patent of the United States, No. 1,869,604,granted to William C. McWhirter on August 2, 1932, for Buifing devicesfor railway switches and the like. -It is believed, therefore, that forthe purposes of the present disclosure the following brief descriptionof the bufling device D will sumce. This bufiing device includes, inaddition to the piston rod 50, a cam shaft 51 extending into the case ofthe device and controlling a valve mechanism not shown. Attached to theouter end of the cam shaft 51 is a crank 52 which is connected by a link53 with the spring rod 14 of the spring connecting rod C. If, when themovable rails 2 and 2 of the switch A are in their normal positions, asshown in Fig. 1, they are moved to their reverse positions by themechanism B, the piston rod 50 will be moved into the device, and thecam shaft 51 will be rotated in a clockwise direction, as viewedfrom'the left in Fig. 1. The construction of the device is such that,under these conditions, the piston rod 50 will be permitted to move withsubstantially no resistance, and the bufling device will therefore exertpractically no retarding action on the rails. Conversely, if the movablerails are moved from their reverse positions to their normal positionsby the mechanism B, the piston rod 50 will be moved outwardly and thecam shaft 51 will be rotated in a counterclockwise direction, as viewedfrom the left in Fig. 1, but due to the construction of the device, noretarding action will again take place. If, however, when the movablerails are in either extreme position, a train trails the switch, the camshaft 51 will remain stationary, and, under these conditions, the actionof the device is such that the movement of the movable rails away fromthe positions which they previously occupied will be unresisted by thebufling device, but that, when the movable rails are being restored tothe positions which they previously occupied, by the spring 15' of thespring connecting rod C, the bufiing device will act to retard thislatter movement.

The switch operating mechanism 13 is mounted on one end of a tie strap18 which is secured to the ties adjacent the outer side of the rail 1,and, as best seen in Figs. 3 and 4, this mechanism, in the form hereshown, comprises a main casing 19 provided with a tail-like projection19 and an auxiliary casing 20 which is secured to the taillikeprojection 19 of the main casing 19. The upper end of the main casing 19is closed by a cover 21 and a guard 22, which cover and guard areremovably secured to the casing by means of studs 23, while the auxilarycasing 20 is closed by a hinged cover 24.

Formed in the main casing 19 is an axially extending rectangularguideway 25 which slidably receives a motion plate 26. The motion plate26 is provided on its upper face with rack teeth 27, and on its lowerface with a cam slot 28, and is adapted to be reciprocated between twoextreme positions by means of a handthrow lever 30 fixed to a shaft 31.The shaft 31 is journaled in suitable bearings 32 secured to the casing19, and has fixed thereto a segment gear 33 which meshes with the rackteeth 27. As best seen in Fig. 3, the cam slot 28 is formed with aportion at each end which is parallel to the direction of movement ofthe motion plate, and. with an intermediate connecting portion which isdisposed at an angle to the direction of movement of the motion plate.Extending into the cam slot 28 and cooperating therewith is a roller 34which is mounted on a pin 35 secured to an arm 36 forming part of acrank 3'7. The crank 37 is journaled in a vertical bearing 38 providedin the bottom of the casing 19 and has fixed thereto on the underside ofthe casing, a removable switch operating arm 37 which is pivotallyattached to the free end of the operating rod 9.

Reciprocably mounted in the casing 19 directly above the motion plate 26is a locking device 39 comprising two spaced parallel side members 39and 39 connected together at their opposite ends by means of integralend members 39 and 39 The left-hand end member 39 carries a rectangularlocking plunger 39 and is formed with two spaced threaded holes 39 and39 while the other end member 39 is provided with three unthreaded holes39*, 39 and 39 two of which holes, 39 and 39 align, respectively, withthe threaded holes 39 and 39 The locking plunger 39 projects with someclearance into a longitudinally extending rectangular slot 44 providedin the tail-like projection 19 of the casing 19, and cooperates at itsinner end with a lock rod L which is slidably mounted in a transverseslot 45 formed in the tail-like projection 19. The lock rod L, in theform here shown, is of standard construction, and comprises twolongitudinally adjustable bars 46 and 47 attached at one end to thefront rod 5 of the switch A, and provided with registering notches 48(see Fig. 5), so disposed that these notches will align with the lockingplunger 39 when and only when the switch A occupies the extreme positionin which it is shown in Fig. 1. The locking device 39 also comprises twobolt members 39 and 39 which pass through the holes 39 and 39respectively, and are screwed into the threaded holes 39 and 39 Thesebolt members also extend with some clearance through holes 40 and 41formed in lugs 42 and 43 secured to the upper face of the motion plate26, and surrounding each bolt member-between the associated lug 42 or 43and the end member 39 is a compressed coil spring 39 which biases thelocking device 39 in the direction to cause the locking plunger 39 toenter the notches 48 in the lock rod L.

Vertical displacement of the locking device 39 and the motion plate 26are prevented by a hold-down member 114 (see Fig. 8) which holddownmember is bolted to the side of the casing 19, and which is provided onits underside near its ends with hold-down surfaces 114 and 114 whichare adapted to slidably engage the upper edges of the side members 39and 39 respectively, of the locking device 39.

For reasons which will become apparent as the description proceeds, theparts of the locking device 39 are so proportioned that when the motionplate 26 is in its left-hand or normal extreme position as shown in Fig.1, the biasing spring 39 will tend to drive the locking device to anextreme position which is beyond the desired locking position. Thelocking device is prevented from moving beyond the desired lookingposition, under these conditions however, by linkage which connects thelocking device with the tie rod 8. As here shown, this linkage includesa plunger bolt 54 which extends with some clearance through the hole 39in the end imember, 39 and'the head of which-bolt engages the left-handside of the end 1 member-39 as :viewed in "Figs; 3 and 4. The threadedend 'of the plunger bolt- 39 is adjustably connected by -means or aturnbuckle 55 (see Fig. 1) with one end of a link 56, theopposite "endofwhichlink -is pivotally connectedwith the long arm" 57 -of abell cranklever 57. The bell crank-lever 57 is pivotally supportedin'a crank stand58, and 'has its-short arm 57* pivotally connected-with 'one'end ofanoperating'rod 59. "The'o'ther end of the-operating-rod 59 is connectedwith the previouslydescribed tie rod 8 by means of-a standard switchbasket 60. The tie rod S -may be: located at any suitable location, butwill-pref- -erably=be located approximately half-way -between the: heeland the point of the switch. "The base 61 of the crank stand 58 issecuredboth to a gauge plate 62 and to .the tie strap 18 upon which themechanism B' is mounted,-and it will be apparent, therefore, that anylossoiadjustmentbetween the parts'due tocreepageoi the 'ties isprevented. The plunger bolt" 54, turn buckle 55, link 56, bell cranklever 57, operating rod 59, spring basket 60, and tierod 8,alsocons'titute meansfor effecting the unlocking of the switch pointsduring a trailin move, as will be made clear presently.

The operation,- as a Whole, of the portion of the apparatus thus fardescribed is as follows: When the hand-throw lever 30 occupies theextremepositionin which it is shown in full lines in Figs; 1

and 3, the motion plate 26 is held in its extreme left-hand or normalposition as viewed in Figs. 3 and 4, and the roller 34 on the crank 37then occupies the right-hand end of the cam slot 28 in the motion plate,so that the crank 13'? is held at the extreme end of its stroke in aclockwise direction, as viewed in Figs. 1 and 3. When the crank37occupies this extreme position, a force is exerted on the movablerails 2 and 2 of the switch through'the medium of the operating rod 9,spring rod 14, nut 17, sleeve 13, spring 15, housing 10,

and the head rod 6, which force holds the mov- -able-rails in theirnormal extreme positions in which they are shown in Fig. 1.Whenthemovable rails are in-their normal positions, the notches 48 inthe lock rod L align with the locking plunger 39 and the locking device39 is therefore moved by the biasing springs 39 to its locking positionin which the locking plunger partly enters the registering notches 48,thus securely lockingthe switch points in their normal positions.

When it is desired to reverse the switch, the hand-throw lever 30 isrotated from the extreme position in which it is shown in full lines-inFig.

1, 'to its opposite extreme or dotted line-position. This movement ofthe lever causes the motion plate 26 to move from its extreme left-handposition, as viewed in Figs. 3 and 4, to its extreme right-handposition. As soon as the motion plate has moved a short distance, thelugs 42 and43 carried thereby engage the left-hand side of theend-member 39 of the locking device 39, and as a result, as the motionplate continues to move, the locking device is moved with the motionplate, thus withdrawing the locking plunger from engagement with thenotches-48 in the lock rod L, and hence unlocking the movable rails 2and 2 The parts are so proportioned that while the locking plunger 39 isbeing withdrawn from engagement with the notches 48 in the lock rod, thecam slot 28 in the motion plate willcontinue to engage the roller 34 onthe crank 37 at that=portion of the slot at its right-hand end which is-parallel t0 the-direction "of movement-of the-niotion plata and'as longas this-portion of the slot is engaging the---roller-,=the crank" 37will remain stationary. :It 'follows, therefore, that during thatportion of themovement'of the motion platewhich isnecessarygtocunlockthe movable rails 0f the switohlno force-is exerted onthese railstending to reverse-them. As soon, however, as this first part :of themovement of the motion plate has .been c'ompleted the-roller 34 is thenengaged by the curved-portion ofthe camslot 28 which causes the crank3-7 to-be rotatedin a counter-clockwise 'directionyasfviewed in'Fig; 3;and as a-result,'the rails are theri' moved to their reverse, positions.'As previously pointed o-ut,-when the rails are movedtotheir reversepositions by the mechanism ':B, the;piston:rod 50= of the buffing deviceD is -ll-10V6'd il1l/O the device, and the camshaft 51 is rotated in aclockwise direction, as viewed frorn the left in-Figl 1, but-dueto theconstruction of this device; thedevice offers substantially-nomesistancetofthe movement of the rails under these conditions. Itishould be'noted-that as long as-the movable :rails remain s'tationa'ry, theplunger bolt 54 remains fixeds0 that during the first part of themovement of the motion plate, the end member 39 ofthe locking-device 39will move out of .engagement-with the head of the plunger bolt. --Assoon" as the -movable rails have started to move, howeverfthe; resultantmovement of the tie rod "kl-acting throughth'e switch basket 60,operating rod 59, bell cranklever57 and link 56 causes the plunger bolttomove inthe same direction as'the motion-"plate is; moving, althoughthe time of motion: and rate of motion of the plunger boltwill hear :nodirect relation to the 1 movementf'of the inotion' plate. During'thefinal movement ofthe motion plate, the portion of the cam slot 28inther'notion plate at the right-hand end-of the slot which is parallelto'the direction-"of movement of the'motionplate engagesAthe-roller 34;which prevents further rotation of' the crank 37, thus lockingthe-movable'rails in their reverse positions".

In order to restore the movable rails to their normal positions afterthey have been reversed as above desoribedythe lever 30 is-restoredto''the pos'itionin which it is 'shownin full linesin the "drawing.'Iheesubsequent movementsofthe parts under these-conditions are just thereverse of "those described above, and it is believed, therefore, thattheo-perationof the'apparatus under these conditions, will be readilyunderstood from an inspection-of the drawings-without further de- Iscription.

"I will now assume that the parts are in their normalpositions, as'shownin the drawings, and that a train trails the switch. As the leadingwheels of the train roll along the 'fixed rail Land the movable rail'2fthe movable rails 2 and Ware forced over laterally, but, before asufficient force is developed to oVer-come'the opposing force of thespring 15 of the spring connecting rod'C and cause the point of themovable rail2 to move out of engagement-with'fixed rail 1, the movablerails beingso-mewhat'resilientbecome bent, so that, with the usualstandard split switch, the tie rod 8 isrnoved upwarclly; as viewed inFig. 1, threequarters of an: inchoramore. This movement of the tiero-dacting thro-uglirthesvn'tch basket 60,. operating'rod 59,,bell-crank lever- 57, link 56, and plungerbolt -59 moves the lockingdevice 39in (opposition to .theubias of :thesprings 39 a :suiii- :cienhamount: to withdraw. the lo'ckingiplunger: 39 zcompletelyiout-ofengagement: with .thexnotches 48 in the lock rod L, thus unlocking theswitch. As a result, when the leading wheels have reached the positionin which a sufi'icient force is developed to cause the point of themovable rail 2 to move out of engagement with the fixed rail 1, theswitch points will be unlocked, and the points will therefore be forcedopen by the wheels in exactly the same manner as would be the case if nofacing point lock were provided, and the buffing' device D will performits usual functionof preventing the movable rails from snapping backafter the passage of each wheel through them. When the train which istrailing the switch has completely passed the switch, the movable railswill slowly return to their normal positions under the bias of thespring 15 of the spring connecting rod C, and against the retardingforce of the buffing device D. During this return movement of themovable rails there will be no deflection of these rails, and thelocking plunger 39 will be moved into engagement with the lock rod Lbefore the movable rails have reached their full normal positions inwhich the'lock rod is in the proper position for the notches 48-tl1ereinto receive the locking plunger. The spring 39 will therefore becomecompressed, and will urge the locking plunger 39 into engagement withthe side of the lock rod, until the notches 48 move into alignment withthe locking plunger, at which time the energy stored in the compressedsprings 39 will force the locking plunger into place in the notches,thus restoring the switch to its normal locked condition. If the notches48 in the lock rod should not come into alignment with the lockingplunger, a suitable indication of this fact will be given by means of acircuit controller E embodying my present invention which circuitcontroller I will describe presently.

During a facing point move, there is no lateral thrust on the movablerails corresponding to, or commensurate with, that which occurs during atrailing movement and what lateral thrust there is will be in thedirection to permit the springs 39 to force the locking plunger furtherinto the notches 48 in the lock rod L.

It will be noted that when the parts are in their normal positions asshown in Fig. 1, the reaction of the biasing springs 39 is transmittedthrough the rack teeth 27 and segment gear 33 to the switch-throw lever30, which tends to raise this lever. However, this lever is so designedthat it has sufiicient weight to resist and overcome this reaction.Furthermore, if it is undesirable for any reason to provide the lever 30with sufficient weight to overcome the reaction of the springs 39, thislever may be held down by a conventional gravity lever latch stand, twoof which stands are indicated at 91 in Fig. 1.

It will also be noted that when the parts are in their normal positionas shown in Fig. 1, since the springs 39 tend to drive the lockingdevice to an extreme position which is beyond its normal lockingposition, but are prevented from doing so by the linkage connecting thelocking device with the tie rod 8, these springs will cause a force tobe exerted on the movable rails at the point where the tie rod 8 isconnected with the rails, and this force which, due to the mechanicaladvantage afforded by the bell crank lever 57, is relatively large, aidsthe force exerted by the spring 15 of the spring connecting rod inrestoring the movable rails to their proper positions after the switchhas been trailed, or after the switch has been operated to its normalposition by the hand lever. In most switch layouts when the movablerails are in their proper normal positions,

the entire length of the movable rail 2 between the tip of the rail andthe point where the tie rod 8 is connected with the rail, will be incontact with the stock rail 1, and in those switch layouts where this isnot the case, fixed stops will usually be provided for the movable rail2 at the point where the tie rod 8 is connected with this rail. It willbe seen therefore, that with apparatus embodying my invention, when themovable rails are in their proper normal positions, the movable rail 2at the point at which the tie rod 8 is attached to this rail will beconstantly urged into engagement with a definite stop by a relativelylarge force, thus insuring that as long as the linkage connecting thetie rod 8 with the locking device is in proper adjustment, and the lockrod L is in proper working order, the locking device will always toreturn to its proper locking position after the switch has been trailed,and will thereafter remain in its proper locking position until theswitch is again trailed, or until the switch is moved away from itsnormal position by the mechanism B.

The circuit controller E referred to herein before is located whollywithin the casing 20, and in the form here shown, comprises a rocker arm66 pivotally supported intermediate its ends on a pin 67 (see Fig. 5)secured within a pair of spaced lugs 68 extending upwardly from thebottom of the casing 20. The rocker arm 66 is disposed directly abovethe locking plunger 39 and is provided with a cam slot 69 whichcooperates with a roller 70 mounted in the upper end of a U- shapedbracket 71. wardly with considerable clearance through a longitudinalslot provided in the bottom of the easing 20 and is secured at its lowerend to the locking plunger 39 It will be seen, therefore, that theroller '70 will be reciprocated in response to reciprocation of thelocking plunger 39 The rocker arm 66 is also provided with a cam face 74which joins the cam slot 69 at the right-hand end of the slot, and whichalso cooperates with the roller 70 in a manner which will be describedhereinafter.

The inner end of the cam slot 69 is radially disposed with respect tothe pivotal axis of the rocker arm 66, but the outer end of this camslot is provided with an offset portion which extends above the rest ofthe slot. The radius of curvature of this offset portion is only alittle larger than the radius of curvature of the roller '70, and theparts are so proportioned that there will be only a small amount ofclearance between the roller and the top and bottom of the cam slot inany position of the roller within the slot. The parts are further soproportioned that when the locking plunger 39 occupies its normallocking position, the roller 70 will engage the cam slot at the centralpart of the offset portion. It will be apparent, therefore, that whenthe switch is properly locked in its normal extreme position, the rockerarm 66 will have been positively rotated in a clockwise direction to anextreme position which I shall term its normal extreme po-- sition. If,however, the locking plunger 39 is moved beyond its normal lockingposition by the biasing springs 39 for any reason, such for example aswould be the case if excess lost motion developed in the linkageconnecting the locking device 39 with the tie rod 8, or if the partswere improperly adjusted, the roller 70 would be forced out of theoffset portion of the cam slot, and into the radial portion, which wouldrotate the rocker The bracket 71 extends downmember 81-.

arm in a counter-clockwise direction from its'nor mal extremeposition'to another extreme positionl, Furthermore, when the lockingplunger? 39 i is withdrawn from the notches'48 in'the lock rod L,theroller 70'wil1 likewisebe forced out of theoft setportion-of the camslot, but underthese conchtions it will move into engagement with thecam face '74:," thus rotating the "rocker arm from its: normalextremeposition to-its counter-clockwise extreme position. It shouldbe'notedthat, dueto' the relatively small radius of curvature oftheoffset portion-f the camslot', this latter rotationof the rocker armwill take place before the lock': ing-plunger 39 has beenmove'dfa'rl'enough'to clear the notches inthe lock rod; The cam 'face: '74isiso designedand the parts" are soproportioned that after the roller'70 has moved into errgagement withthe cam'iace 74:;I1Uflllth8l rota--tion of the rocker arm will take-"place "untilthe locking plunger 39is'subsequently restoredto-its normal locking position, at" which timethe roller: 70 will engage the lower face 69% of the-cam s1ot 69 andwill positively restore the rocker: arm to its normal extreme position.I

Pivotally attached to the left-hand end-of. the rockerarm 66is a contactoperating mem'ber YE. This contact operating member" is mountedvto movevertically on studs '76 which project'upe wardly from the-bottom of the'casing -20, andv which pass freely throug-hholes "75 inthe operate ingmember; Secured to the upper side ofthe operating member 75 are twosuperposed insulate ing" blocks 78 and79 between which are clamped thefree ends of'a plurality of flexible contact fingers 80, here shown asfour in number. Each Contact finger 80-cooperates-withan associated"contact member 81t0 form a plunger lock contact 80-8l. Each contactfinger SO 'and'theassO- ciated contact member .81. are clampedto theopposite sides of an insulating block 82 by means of terminal posts 83and-84;--ancl the insulatin'gr block 82, in turn; issupported onlugs-85'projectv ing inwardly: from the sides of the housing 20.: Eachterminal post 84 is electrically connected: with the associated contactmember 81,- -but-is in sulatedfrom the associated contact finger 80aswill beapparent from an inspection of thedraw ing, ,while each terminal"post- 83-is insulated from? both the associated'contact finger 80"andcontact The parts are so: proportioned that: when the rocker arm'66occupies its normal ex'-- treme position in which it is shown in thedraw-- ing. each-plunger lock contact 80-"-81-wil1' be closed, but that,when the-rocker'arm is rotated to its other extreme position, eachcontact30-8l will then become opened. It will be :apparent;thereforathat the plunger lock contactswill be: closed when and onlywhen the-locking plunger: 39 -occupiesits normal locking position,

Associated with each plunger lock contact 8081 is a pointdetector'contact comprisinga flexible contact. finger 86 whichcooperates with a fixed contactmem'ber- 87-. Each contact finger: 861 isfastened at one endjto. a conductingstrip 88', the-other endofwhich'stripis clamped against the fixed end of 'theassociated finger 80-to: makeielectrical contact therewith; :While-each' contact'member 87 issecured to, and electricallyconnected with, the associated-terminalpost83.

Pivotally mounted below-the contact fin'gers86 is? a second contactoperating-member s (see- Figs 5 and 6)"carryinga rolIer-QO Wh-ich attimes enters a notch 91 in a point detector rod 63; The :point detectorrod 63 is slidably mounted in the casing- 20 and as shown in Fig.1is'attachedpby means:

and 'areproperly locked in these positions.

of a link-6e anda bolt member-65 to themovable rail 2 of the switch A-inthe usual and well-known manner. The operatingmember'SQ also carries aninsulating strip 92which cooperates with the movablecontact. fingers 86in such manner that whentlie roller"90 is Within the notch91 in thepointidetector'rod 63, the insulating strip '92 will be: clear ofthemovable contact fingers 86, so that thelcontacts 86-8'7 will thenbeclosed, but that-, when theroller QO'is forced out of the notch- 9l,this strip will engage the underside of the fingers 86 and raise them tothe positions in which theytare' out of.-enga'gement with the associatedfixed contact members 87, thus opening the contacts 86 -87. The notch 91in the point detector ro'd' fia is so'l'disposedand the parts are soproportioned that the roller 90 will enter the notch 91 when and onlywhen the movable rails 2 and 2- of'lithe switchiA occupy their normalextreme positions; and the rail '2 is in proper engagement with thefix'ed rail 1.

As is wellunderstood, "the contacts of a circuit controller of the typedescribed are utilized to controlsignals governin'g traflic over theswitch; and their primary purpose is to cause the signal toindicateflstopi unless-the switch points occupy their proper positionsrelative to the fixed'rails With the portionot the circuit controllerthus far described; thesecontacts will adequately do this inallinstances' where the apparatus is in proper working order. However, ifdue to some failure of the operatingmechanism', the lockingplu'nger 39does-not become completely withdrawn from thenotches48 in-the lock rod.L in the normal manner while a train is tr'ailing the-switch, a dangerous con'dition might possibly exist, because under these-conditions;while the switch points will be displaced at the top an amount whichwould easily operate-the pointdetector contacts of the circuitcontroller if the detectorrod could be-connected wi-th the pointsatfithe top" of-the points, it is necessary for clearancareasons toconnect the: detector rod to the switch points some distance below thetop -'of the points; whera due to the" rolling of- 1 the zpoints :duringthe trailing, the amountof the -mo'vem'ent may not be more than one-halfof that occurring at the top of the points and fur'thermore', after atrain 'has trailed the switch;- the points will usually. spring back"-toward-their 'original t-positionsa certain amount. As-a :result,thefinal displacement of the' point detectorrod-mayibe very little, ifany, more than the displacement which would correspond to 'a.

maximum permissible I opening of the closed switch po'int;=which isthesetting at which the point detector contacts becomeopened, while'theopeningoflthe closed pointiat the'top might be suffi'cientto beextremely dangerous forsubsequent high speed: train movements: In 'orderto insure that this dangerous'condition will be de-- te'cted'gI provid'elatching mechanism so constructed that if-the switch fails to becomeunlocked while 1 the train is trailingthe switch, this latch in'gmechanismwill retain theindication contacts in 'th'eiroperated positionsuntil they are subsequently releas'ed by -a maintainerh even'thoughxtheswitch points'spring back toward theiraproper positions after 1 thetrain has trailed throughthe'switch,.the signals governing trafficover'rthe switchtwill' continuexto display a restrictive'indicationwuntil the maintainer releasesr the-contacts of the circuitcontroller andpermits them .toIreturn-to their normal positions; It is.assumed that before the maintainer-does this,

he will inspect the switch points, and, if damaged, repair them, thusguarding againsta dangerous condition due to damaged switch parts.

Referring now again to Figs. 3 and 4, the latching mechanism justreferred to comprises a latch arm 107 which is secured at its left-handend to the contact operating member 89, and which extends toward theright from the pivotal axis of this operating member. A latch dog 106 isprovided on the extreme right-hand end of the latch arm 107, andcooperating with this latch dog is a latch catch 100 having a screwthreaded upper portion 100 which is adjustably screwed through a tappedhole 95 in a latching member 95. The latch catch is also provided with arectangular latch head 100 having its opposite sides cut away to formtwo notches 104 and 105, and the latch catch is adapted to be locked, bymeans of a lock washer 101 and a jam nut 102 provided on the threadedportion 100 above the latching member 95, in an adjusted position inwhich either the side of the latch head 100 containing the notch 104, orthe opposite side, faces the latch dog. To facilitate adjusting thelatching member, the upper end of the threaded portion 100 is providedwith a saw kerf 100 for the reception of a screw driver.

The latching member 95 extends transversely of the casing 20 directlyabove the left-hand end of the rocker arm 66, and is pivotally supportedat its ends on trunnion screws 96 which are adjustably mounted in bosses97 formed in theside walls of the casing 20. A substantially horizontalcam arm 108 extends toward the right from the latching member 95 and isprovided adjacent its righthand end with two converging downwardlyextending cam faces 111 and 112 which cooperate, under certainconditions later to be described, with the roller carried by the lockingplunger 39 The cam arm 108 also serves to overbalance the latchingmember, so that the latching member tends to constantly rotate in aclockwise direction about the trunnion screws.

The latching member 95 is further provided with 2. depending leg 109(see Fig. 7) carrying a horizontal latching foot 110 which extendsunderneath the rocker arm 66. The latching foot 110 coacts with thelower end of a latching plunger 113 which extends upwardly throughiconcentric holes 114 and 115 (see Fig. 5) formed in an upwardlyprojecting portion provided in the left-hand end of the rocker arm 66.The hole 114 is made considerably larger in diameter than the hole 115since hole 114 is adapted for the reception of a coil spring 116 whichsurrounds the latching plunger 113 between the upper end of the hole 114and a guide 11'! which is secured to the plunger. The spring 116biasesthe latching plunger to a lowermost position in which it isstopped by a nut 118 screwed onto the upper end of the latching plungerabove the hole 115.

The parts of the latching mechanism are so proportioned, and. the latchcatch 100 is so adjusted that when the roller on the contact operatingmember 89 is within the notch 91 in the point detector rod 63, and thelocking plunger 39 is within the notches 48 in the locking rod L, asshown in the drawings, the latch head 100 of the latch catch 100 willengage the end of the latching dog 106 on the latch arm 107 just abovethe notch 104, and will thus prevent the latching member from rotatingin a clockwise direction past the position in which it is shown in thedrawings. In order to prevent vibration and consequently wear-betweenthe latch catch and the latching dog due to the passage of trains overthe switch when the parts are in these positions, a spring 119 isstretched between a depending lug 120 on the operating member 89, and alug 121 formed on the-side of the leg 109 of the latch member. It willbe seen that this spring increases the normal tendencyof the latchingmember to rotate in a clockwise direction, and the tendency of theoperating member 89 to rotate in a counter-clockwise direction, so thatthe latch catch is normally held firmly against the end of the latchingdog, and the latching dog is prevented from vibrating up and down.

In explaining the operation of the circuit controller as a whole, I willfirst assume that the switch points are locked in their normal positionsand that a train trails the switch. I will also assume that while thetrain is trailing the switch, the locking mechanism functions in themanner previously described so that the locking plunger 39 becomes fullywithdrawn from the notches 48 in the lock rod L and unlocks the switchpoints before the switch points are forced open by the wheels of thetrain, and that after the train has completely trailed the switch andthe switch points have been returned to their normal positions by thespring 15 of the spring connecting rod C, the locking plunger isrestored to its normal locking position to relock the switch points intheir normal positions. tions, as soon as the locking plunger 39 startsto move toward its unlocking position due to engagement of the wheels ofthe train with the movable rails of the switch, roller 70 will rotaterocker arm 66 in a counter-clockwise direction from its normal extremeposition to its other extreme position in the manner previouslydescribed, and this rotation of the rocker arm will open the plungerlock contacts. This rotation of the rocker arm will also cause thelatching plunger 113 to move into engagement with the upper side of thelatching foot 110, thus forcing the latching plunger upwardly inopposition to the bias of spring 116. When the locking plunger 39reaches the position where it is just clear of the lock rod L, roller'70 will move into engagement with cam face 111 of cam arm 108, and asthe latching plunger continues its movement, cam. arm 108 will berotated in a counter-clockwise direction by the roller 70. This rotationof the cam arm, in turn, will rotate the latching member to a positionin which the latch catch is out of engagement with latching dog 106, andin which the latching foot is clear of the right-hand side of thelatching plunger 118. As soon as the latching foot 110 clears thelatching plunger, the spring 113 will force the latching plunger to itslowermost position, and as a result, when the roller 70 has movedcompletely past the cam face 111 on the cam arm 108, the latchingplunger 113 will engage the latching foot 110 at the left-hand side ofthe latching foot and will thus hold the latching member 95substantially in the extreme position to which it was previously movedby the roller 70. When the switch points are next forced open by thetrailing train, the roller 90 on the contact member 89 will be forcedout of the notch 91 in the point detector rod, which action will rotatethe operating member 89 to the position in which the point detectorcontacts 8687 become opened. The parts will then remain in the positionswhich they then occupy until the train has completely trailed the switchand the switch points have started to return to their normal positions.When this hap- Under these condipens, -the locking plunger will, ofcourse, start to. return to-its normal locking position, andduringthefirst part of this return movement, the roller '70 will engage the camface 112 on the cam-arm. 108, andwill raise the cam arm- 108 slightly,so

that the latching member 95 will be rotated through a small anglein acounter-clockwise direction from the position where it is stopped byengagement of the latching plunger 113 with the left-hand side of thelatching foot 110. As soon,

however, as the roller '70 has moved past the cam which it is shown inthe drawings.

face ,112, the latching member will return by gravity to itslatched'position. Shortly after the roller passes the cam face 112, theendpoint detector contacts will close and the latch arm'lfl'lwillberestored to its normal position in When the switch points reach theirfull normal position,

the notches 48 in the lock rod L will then align with the lockingplunger and will allow the lock ing plunger to snap into its normallockingposition under thev action of the biasing springs 39 in themanner previously described. As the locking plunger thus completes itsreturn stroke, roller 70 will'engage cam surface 69 of cam slot 69' inrocker arm 66, and will thus rotate the rocker arm to its normalposition. This rotation of the rocker arm, in turn, will cause theplunger lock contacts -81 to close, and will also raise thelockingplunger 113 to the positioninwhich it is out of engagement with thelatching foot 110.- As soon as the latching plunger has moved out ofengagement with the latch foot, the latch-,

ingmember will return, under the influence of gravity and the'bias ofthe spring 119, to the position in which the latch catch engages the endof the latching dog 106, and all parts of the circuit controller willthen be restored to their normal positions in which-they are shown inthe drawings.

Where the parts are in the positions in'which they are shown in thedrawings,- and the switch is operated to its reverse position by meansof the hand throw lever 30,- the operation of the circuit controllerwill be similar to that just described for a trailing movement up to thepoint where V the switch points start to return to their normalpositions.

Likewise, after theswitch' points have been movedto their reversepositions by the"hand-' throw lever, and the hand-throw lever issubsequently operated to restore the switchpo-ints 'to their normalpositions, the operation of the circuitcontroller will be similar tothat "just described fora trailing movement from the point where theswitch points have started to'return to their normal positions.

I will now assume that a train trails the switch,

I and'that the mechanism is so far out of adjustment that the lockingplunger remains in its normal "locking position during the entire timethe train is trailing the switch. Under these conditions, the plungerlock contacts 80 -81 will remain closed, but due to the extreme forceswhich" are exerted on the switch points by the trailing train, the pointdetector rod will be moved upwardly as viewedin Fig. 2 far enough tocause the roller 90on the contact operating member -89 to move out ofthenotch'elin. the lock rod L. As a-result, the operatingmember 89 willbe rotated to-the position in which the point detector contacts becomeopened, andin which the latch dog 106 onthe latch arm 107' alignswiththenotch 104 in the latch catch-100. Thelatchingmember95 will therefore nowrotate, due to its bias, to the position-in which the latch dog- 106enters the notch 104 in the latch. catch.100.. It will be apparent froman'inspectionof the drawings that when the latch dog 106 has onceentered the notch 104 in the latch catch l00, the operating member 89will be held in the position in which the point detector contacts areopen until the latch catch is subsequently moved outqof engagement withthe latch dog even if the pointdetector; rod subsequently returns to'thepositionrin' which the notch 91 aligns with the roller 90.- It followsthat in order to releasethe operating member and permit the pointdetector contacts-tobecome-closedafter they have once been opened in'themanner just described, ityis necessary to'restore-the latching member 95to itsnormal position in which it is shown in the drawings.- This maybe-done either by removing the hinged cover 24 from the casing 20 andraising 111118103111. arm, 108' manually, or by throwing theswitchmovement by hand to its reverse position,xin which latter case,.roller70 will raise the cam arm and thus release the, operating member;.Whenthe point detector contacts are .released by.. thro.wing,.the:switchmovement to its reverse position by' hand, if the switch pointshaveibeen distorted' at all by. the trailing'train,

the :locking plunger willnot reenter the "lock-rod thatqthe lockingplunger is partly withdrawn from r engagement with the notches 48 in thelock rod Lflbut is not moved far enough to clear the notches, theapparatus will still operate to latch the point detector contacts 'openuntil they are subsequently manually released.- Under theseconditions-theoperation of the mechanism will bethesame as that justdescribedwith the exception that the, rocker arm 66' will now be rotatedfrom its normal extreme position to its other extreme position, so thatthe latching plungerllB will be moved upwardly by .engage-- mentfof thelatching plunger with the'latching foot-;1-10'. -'This engagement of thelatching" plunger with the. latching foot 110 will not pre vent-thelatching device from rotating to its latching-i position, as mightappear on firstthought, but" on 'the-contrary, the end of the latchingplunger andthe top of the latching footare disposed at such an angle asto tend to urge the latching member 95 toward its latching position.Itwill be seen,- therefore, that when the switch points are forced open,thus rotating the operatingmember. 39in a clockwise direction to theposition in which the point detector contacts are forced .open, thelatching member .95 will:be= rotated to the position in which the latchdog 106 enters the'notch 104 in exactly the same manner as it wasrotated when the plunger remained in its normallatching position. Whenthe latching member h as beenrotated to the po sition in which the latchdog 106 enters the notch 104 in the latch catch 100, the point detectorcontacts will then be held open until the latching member issubsequently restored to its normal position in the manner previouslydescribed.

Although I have herein shown and described only one form of circuitcontrollers embodying my invention, it is understood that variouschanges and modifications may be made therein within the scope of theappended claims without departing from the spirit and scope of myinvention.

Having thus described my invention, what I claim is:

1. In combination, a spring switch, a lock rod connected with the switchand provided with a notch, a locking plunger biased to a position inwhich it will enter the notch in said lock rod when and only when theswitch occupies one extreme position, means for at times withdrawingsaid locking plunger from said notch to unlock said switch, a contact,means for operating said contact when said switch is moved away fromsaid one extreme position, and means for latching said contact in itsoperated position if and only if the movement of the contact to itsoperated position is due to the switch being moved away from said oneextreme position by a train trailing the switch while the switch islocked in said one extreme position.

2. In combination, a spring switch, a lock rod connected with the switchpoints to move therewith and provided with a notch, a locking plunger,means for at times moving said locking plunger into the notch in saidlock rod to lock the switch points in one extreme position and for atother times withdrawing said locking plunger from said notch to unlockthe switch points, a normally closed contact, means effective if theswitch points are moved away from said one position when said lockingplunger is within said notch for latching said contact open, and meanseffective upon withdrawal of said locking plunger from the notch in saidlock rod after said contact has been latched open for unlatching saidcontact.

3. In combination, a spring switch, a lock rod connected to the switchpoints to move therewith, a locking plunger movable between a lockingand an unlocking position and effective when in its locking position forengaging said lock rod to lock said switch in its normal position,means-for moving said locking plunger between its locking and unlockingpositions, a contact operating member movable between two positions andbiased to one position, means for moving said contact operating memberfrom its one position to its other position whenever said switchoccupies any position but its normal position, a contact controlled bysaid contact operating member, and means for latching said contactoperating member in its other position if said contact opcrating memberis moved-to its other position when said locking plunger occupies itslocking position.

4. In combination, a spring switch, a lock rod connected to the switchpoints to move therewith, a locking plunger movable between a lookingand an unlocking position and effective when in its locking position forengaging said lock rod to lock said switch in its normal position, meansfor moving said locking plunger between its.

locking and unlocking positions, a contact operating member movablebetween two positions and biased to one position, means for moving saidcontact operating member from its one 130 sition to its other positionwhenever said switch occupies any position but its normal position, acontact controlled by said contact operating member, means for at timeslatching said contact operating member in its other position when saidcontact operating member is moved to its other position, and means forrendering said latching means inefiective when said locking plungeroccupies its locking position.

5. In combination, a spring switch, a lock rod connected to the switchpoints to move therewith and provided with a notch, a locking plungermovable into and out of engagement with said notch when and only whenthe switch occupies its extreme normal position, means for moving saidlocking plunger into and out of engagement with said notch, a contactoperating member movable between two positions and biased to oneposition, means for moving said contact operating member from its oneposition to its other position whenever said switch occupies anyposition but its normal position, a contact controlled by said contactoperating member, means for at times latching said contact operatingmember in its other position, and means for rendering said latchingmeans ineffective except when said looking plunger is in engagement withsaid notch in said lock rod.

6. In combination, a spring switch, a lock rod connected with the switchpoints to move therewith and provided with a notch, a locking plunger,means effective when said switch occupies its normal position forbiasing said locking plunger to a locking position in which it entersthe notch in said lock rod, means for at times moving said lockingplunger to an'unlocking position in which the plunger is withdrawn fromthe notch in said lock rod, a pivoted contact operating member biased toone position and provided with a roller, a point detector rod connectedwith the normally closed switch point and provided with a notch which isadapted to receive said roller when and only when said switch occupiesits normal position, a contact controlled by said contact operatingmember, and latching mechanism controlled in part by said lockingplunger and cooperating with said contact operating member in suchmanner that if said roller is forced out of the notch in said pointdetector rod while said locking plunger is within the notch in said lockrod said contact operating member will subsequently be held in theposition in which the roller is out of the notch in the point detectorrod until the latching mechanism is operated to release the contactoperating member.

7. In combination, a spring switch, a lock rod connected to the switchpointsto move therewith and provided with a notch, a locking plungermovable into and out of engagement with said notch when and only whenthe notch occupies its extreme normal position, means for moving saidlocking plunger into and out of engagement with said notch, a contactoperating member movable between two positions and biased to oneposition, means for moving said contact operating member from its oneposition to its other position whenever said switch occupies anyposition but its normal position, a contact controlled by said contactoperating member, a latch arm secured to said contact operating memberand provided with a latch dog, a latch catch biased to one position andmovable to said one position when and only when said operating memberconnected to the switch points to move therewith and provided with anotch, a locking plunger movable into and out of engagement with saidnotch when and only when the switch occupies its extreme normalposition, means for moving said locking plunger into and out ofengagement with said notch, a contact operating member movable betweentwo positions and biased to one position, means for moving said contactoperating member from its one position to its other position wheneversaid switch occupies any position but its normal position, a contactcontrolled by said contact operating member, a latch arm secured to saidcontact operating member and provided with a latch dog, a pivotedlatching member provided with a depending latch catch having a latchhead containing a notch, means for biasing said latching member to sucha position that when said contact operating member is moved to its otherposition said notch will receive said latch dog and latch said contactoperating member in its other position, and means controlled by saidlocking plunger for rotating said latching member away from the positionto which it is biased whenever said locking plunger is withdrawn fromthe notch in said lock rod.

9. In combination, a spring switch, a lock rod connected wlth the switchpoints to move therewith and provided with a notch, a locking plungeradapted to enter the notch in said lock rod when and only when theswitch occupies its normal extreme position, said locking plunger beingmovable within said notch to an extreme position which is beyond itsnormal locking position, means for moving said locking plunger into andout of engagement with said notch, a roller secured to said lockingplunger, a pivoted rocker arm provided with a cam slot which receivessaid roller, said cam slot being so designed that when said lockingplunger occupies its locking position said rocker arm will be rotated toone extreme position but that if said locking plunger is moved beyond,or is withdrawn from, its looking position said rocker arm will berotated to another extreme position, a plunger lock contact operated bysaid rocker arm, a point detector rod provided with a notch, a contactoperating mem-- ber provided with a roller which aligns with the notch,in said point detector rod when and only when the switch occupies itsnormal extreme position, said contact operating member being biased to aposition in which the associated roller will enter the notch in saidpoint detector rod when this roller aligns with this notch, a contactoperated by said contact operating member, a pivoted latching member, acam arm secured to said latching member and biasing said latching memberto a latching position, said cam arm being provided with cam faces whichcooperate with the roller secured to said locking plunger to rotate saidlatching member to a second position when said locking plunger'iswithdrawn from the notch in said lock rod, a depending leg on saidlatching member provided with a latching foot which extends underneathsaid rocker arm, a latching plunger mounted in said rocker arm andbiased to one position and cooperating at its lower end with saidlatching foot in such manner that if said latching member is moved toits second position when said rocker arm occupies its other extremeposition said latching plunger will engage said latching foot and holdsaid latching member in its second position until said rocker arm issubsequently returned to its one extreme position, a latch arm securedto said contact operating member and provided with a latch dog, and alatch catch secured to said latching member and provided with a latchhead containing a notch which is adapted to receive said latch dog whenand only when said contact operating member occupies the position inwhich said roller is out of the notch in said point detector rod andsaid latching member is rotated to its latching position, the partsbeing so proportioned that when said notch is receiving said latch dogsaid contact operating member will be held in the position in which saidroller is out of the notch in said lock rod.

HERBERT L. BONE.

